248 lines
8.0 KiB
C++
248 lines
8.0 KiB
C++
/* ------------------------------------------------------------------
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* Copyright (C) 1998-2009 PacketVideo
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
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* express or implied.
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* See the License for the specific language governing permissions
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* and limitations under the License.
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* -------------------------------------------------------------------
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*/
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/*
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------------------------------------------------------------------------------
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PacketVideo Corp.
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MP3 Decoder Library
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Filename: pvmp3_mpeg2_get_scale_data.cpp
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Date: 09/21/2007
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------------------------------------------------------------------------------
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REVISION HISTORY
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Description:
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------------------------------------------------------------------------------
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INPUT AND OUTPUT DEFINITIONS
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Input
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mp3SideInfo *si, side information
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int32 gr, granule
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int32 ch, channel
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mp3Header *info, mp3 header information
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uint32 *scalefac_buffer,
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uint32 *scalefac_IIP_buffer,
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tbits *pMainData bit stream Data
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Returns
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uint32 *scalefac_buffer, acquired scale band data
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uint32 *scalefac_IIP_buffer, auxiliary scale data
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------------------------------------------------------------------------------
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FUNCTION DESCRIPTION
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get scale data for mpeg2 layer III LSF extension
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------------------------------------------------------------------------------
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REQUIREMENTS
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------------------------------------------------------------------------------
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REFERENCES
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[1] ISO MPEG Audio Subgroup Software Simulation Group (1996)
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ISO 13818-3 MPEG-2 Audio Decoder - Lower Sampling Frequency Extension
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------------------------------------------------------------------------------
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PSEUDO-CODE
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------------------------------------------------------------------------------
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*/
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/*----------------------------------------------------------------------------
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; INCLUDES
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----------------------------------------------------------------------------*/
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#include "pvmp3_mpeg2_get_scale_data.h"
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#include "pvmp3_getbits.h"
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/*----------------------------------------------------------------------------
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; MACROS
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; Define module specific macros here
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----------------------------------------------------------------------------*/
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/*----------------------------------------------------------------------------
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; DEFINES
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; Include all pre-processor statements here. Include conditional
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; compile variables also.
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----------------------------------------------------------------------------*/
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/*----------------------------------------------------------------------------
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; LOCAL FUNCTION DEFINITIONS
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; Function Prototype declaration
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----------------------------------------------------------------------------*/
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/*----------------------------------------------------------------------------
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; LOCAL STORE/BUFFER/POINTER DEFINITIONS
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; Variable declaration - defined here and used outside this module
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----------------------------------------------------------------------------*/
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const uint32 nr_of_sfb_block[6][3][4] =
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{ {{ 6, 5, 5, 5}, { 9, 9, 9, 9}, { 6, 9, 9, 9}},
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{{ 6, 5, 7, 3}, { 9, 9, 12, 6}, { 6, 9, 12, 6}},
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{{11, 10, 0, 0}, { 18, 18, 0, 0}, {15, 18, 0, 0}},
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{{ 7, 7, 7, 0}, { 12, 12, 12, 0}, { 6, 15, 12, 0}},
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{{ 6, 6, 6, 3}, { 12, 9, 9, 6}, { 6, 12, 9, 6}},
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{{ 8, 8, 5, 0}, { 15, 12, 9, 0}, { 6, 18, 9, 0}}
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};
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/*----------------------------------------------------------------------------
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; EXTERNAL FUNCTION REFERENCES
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; Declare functions defined elsewhere and referenced in this module
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----------------------------------------------------------------------------*/
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/*----------------------------------------------------------------------------
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; EXTERNAL GLOBAL STORE/BUFFER/POINTER REFERENCES
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; Declare variables used in this module but defined elsewhere
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----------------------------------------------------------------------------*/
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/*----------------------------------------------------------------------------
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; FUNCTION CODE
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----------------------------------------------------------------------------*/
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void pvmp3_mpeg2_get_scale_data(mp3SideInfo *si,
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int32 gr,
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int32 ch,
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mp3Header *info,
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uint32 *scalefac_buffer,
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uint32 *scalefac_IIP_buffer,
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tmp3Bits *pMainData)
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{
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int16 i;
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int16 j;
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int16 k;
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int16 blocktypenumber = 0;
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int16 blocknumber = 0;
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granuleInfo *gr_info = &(si->ch[ch].gran[gr]);
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uint32 scalefac_comp, int_scalefac_comp, new_slen[4] = { 0,0,0,0 };
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scalefac_comp = gr_info->scalefac_compress;
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if ((((info->mode_ext &1)) && (ch == 1)))
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{
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/* intensity_scale = scalefac_comp %2; */
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int_scalefac_comp = scalefac_comp >> 1;
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if (int_scalefac_comp < 180)
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{
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new_slen[0] = int_scalefac_comp / 36;
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new_slen[1] = (int_scalefac_comp % 36) / 6;
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new_slen[2] = int_scalefac_comp % 6;
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blocknumber = 3;
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}
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else if (int_scalefac_comp < 244)
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{
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int_scalefac_comp -= 180;
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new_slen[0] = (int_scalefac_comp & 63) >> 4;
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new_slen[1] = (int_scalefac_comp & 15) >> 2;
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new_slen[2] = int_scalefac_comp & 3;
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blocknumber = 4;
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}
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else if (int_scalefac_comp <= 255)
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{
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int_scalefac_comp -= 244;
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new_slen[0] = (int_scalefac_comp) / 3;
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new_slen[1] = (int_scalefac_comp) % 3;
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new_slen[2] = 0;
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blocknumber = 5;
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}
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new_slen[3] = 0;
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si->ch[ch].gran[gr].preflag = 0;
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}
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else
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{
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if (scalefac_comp < 400)
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{
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new_slen[0] = (scalefac_comp >> 4) / 5;
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new_slen[1] = (scalefac_comp >> 4) % 5;
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new_slen[2] = (scalefac_comp & 15) >> 2 ;
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new_slen[3] = (scalefac_comp & 3);
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si->ch[ch].gran[gr].preflag = 0;
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blocknumber = 0;
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}
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else if (scalefac_comp < 500)
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{
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scalefac_comp -= 400;
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new_slen[0] = (scalefac_comp >> 2) / 5;
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new_slen[1] = (scalefac_comp >> 2) % 5;
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new_slen[2] = scalefac_comp & 3;
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new_slen[3] = 0;
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si->ch[ch].gran[gr].preflag = 0;
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blocknumber = 1;
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}
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else if (scalefac_comp < 512)
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{
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scalefac_comp -= 500;
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new_slen[0] = scalefac_comp / 3;
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new_slen[1] = scalefac_comp % 3;
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new_slen[2] = 0 ;
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new_slen[3] = 0;
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si->ch[ch].gran[gr].preflag = 1;
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blocknumber = 2;
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}
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}
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if (gr_info->block_type == 2)
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{
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if (gr_info->mixed_block_flag)
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{
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blocktypenumber = 2;
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}
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else
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{
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blocktypenumber = 1;
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}
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}
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k = 0;
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for (i = 0; i < 4; i++)
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{
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if (new_slen[i])
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{
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for (j = 0; j < (int16)nr_of_sfb_block[blocknumber][blocktypenumber][i]; j++)
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{
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scalefac_buffer[k] = getNbits(pMainData, new_slen[i]);
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scalefac_IIP_buffer[k] = (1L << new_slen[i]) - 1;
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k++;
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}
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}
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else
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{
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for (j = 0; j < (int16)nr_of_sfb_block[blocknumber][blocktypenumber][i]; j++)
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{
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scalefac_buffer[k] = 0;
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scalefac_IIP_buffer[k] = 0;
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k++;
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}
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}
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}
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}
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